Irradiation-induced IFN-type-I pathway activation in prostate cancer cell lines.

The Interferon (ΙFN) Type-I pathway has an important role in the activation of an anti-tumor immune response. We investigated the effects of two different dose fractionations of radiation (3 daily 8 Gy fractions vs. one fraction of 20 Gy) on the activation of the Type-I IFN-pathway in three hormone-dependent (22Rv1) and independent (DU145, PC3), prostate cancer (PC) cell lines. Regardless of the dose schedules, radiation-induced the expression of IFN-stimulated genes in all PC cell lines, with a strong up-regulation of the IFI6v2 and IFI44 genes. In addition, strong up-regulation of the MX1 and MX2 genes was noted in the PC3 cell line. This effect was independent of the expression of IFNß, cGAS, or TREX1 levels. It is suggested that the RT-induced IFN type-I response could be exploited for the development of immuno-RT policies for localized and metastatic PC.

Apalutamide radio-sensitisation of prostate cancer.

INTRODUCTION: The combination of radiotherapy with bicalutamide is the standard treatment of prostate cancer patients with high-risk or locally advanced disease. Whether new-generation anti-androgens, like apalutamide, can improve the radio-curability of these patients is an emerging challenge. MATERIALS AND METHODS: We comparatively examined the radio-sensitising activity of apalutamide and bicalutamide in hormone-sensitive (22Rv1) and hormone-resistant (PC3, DU145) prostate cancer cell lines. Experiments with xenografts were performed for the 22Rv1 cell line. RESULTS: Radiation dose-response viability and clonogenic assays showed that apalutamide had a stronger radio-sensitising activity for all three cell lines. Confocal imaging for γΗ2Αx showed similar DNA double-strand break repair kinetics for apalutamide and bicalutamide. No difference was noted in the apoptotic pathway. A striking cell death pattern involving nuclear karyorrhexis and cell pyknosis in the G1/S phase was exclusively noted when radiation was combined with apalutamide. In vivo experiments in SCID and R2G2 mice showed significantly higher efficacy of radiotherapy (2 and 4 Gy) when combined with apalutamide, resulting in extensive xenograft necrosis. CONCLUSIONS: In vitro and in vivo experiments support the superiority of apalutamide over bicalutamide in combination with radiotherapy in prostate cancer. Clinical studies are encouraged to show whether replacement of bicalutamide with apalutamide may improve the curability rates.

HIF1α-dependent and independent pathways regulate the expression of PD-L1 in prostate cancer.

PD-L1/PD-1 pathway is a major pathway exploited by human cancer types, which is a target for current immunotherapy. We investigated tumor microenvironmental factors involved in PD-L1 induction in prostate cancer (PC). We studied the expression of PD-L1 in a series of 66 PCs, in parallel with the expression of hypoxia- and acidity-related immunohistochemical markers (Hypoxia-inducible factor HIF1α, and lactate dehydrogenase LDHA) and tumor-infiltrating lymphocyte TIL density. Experiments with three PC cell lines, the 22Rv1, DU145, and PC3 were conducted focusing on the inducibility of PD-L1 by hypoxia, acidity, lymphocyte interactions, and radiation. In tissues, PD-L1 expression by cancer cells was directly related to PD-L1 expression by TILs and macrophages (p < 0.05), and the overexpression of HIF1α and LDH5 (p < 0.05). TIL density was inversely related to ΗΙF1α (p = 0.02). Exposure of PC cell lines to hypoxia strongly induced PD-L1 and protein and mRNA levels, directly controlled by HIF1α function (p < 0.001). Irradiation with 20 Gy had no apparent effect on PD-L1 expression. Culturing PC cell lines with culture medium (CM) from PBMCs strongly induced PD-L1 at protein and mRNA levels, independently from HIF1α, which was also confirmed when cells were incubated with Interferon-γ (p < 0.001). It is concluded that the combination of anti-PD-L1/PD-1 immunotherapy with hypoxia/HIF-targeting may be important in the treatment of specific subgroups of PC patients.

Radiobiological analysis of preliminary results of a phase II study of pelvic hypofractionated and accelerated radiotherapy for high-risk prostate cancer patients.

PURPOSE: Conventionally fractionated radiotherapy (CRT) is widely applied for the treatment of high-risk prostate cancer. Pelvic node irradiation improves control of the disease. Although the therapeutic guidelines support the use of hypofractionated and accelerated radiotherapy (HypoAR), this is addressed to prostate and seminal vesicles. At the same time, the safety and efficacy of HypoAR for pelvic node irradiation remain obscure. Material and Methods: In a phase II study, we evaluated the feasibility of pelvic HypoAR in 22 high-risk prostate cancer patients. The RT scheme delivers 14 consecutive fractions of 3.67 Gy (total 51.38 Gy) to the prostate, 3.5 Gy (total 49 Gy) to the seminal vesicles, and 2.7 Gy (total 37.8 Gy) to the lymph nodes, using image-guided volumetric modulated arc therapy. A comparative radiobiological analysis of dose-volume histogram is performed (HypoAR vs. hypothetical equivalent CRT regimens, without and with time correction). RESULTS: Our clinical experience shows impressively low early and short-term late toxicities, without any grade III events, within a median follow-up of 30 months. Only one biochemical relapse was recorded 30 months after irradiation. In radiobiological analysis, considering an α/ß-value of 4 Gy and a λ-value of 0.2 Gy/day for late effects, all comparisons predicted significantly lower toxicity for the HypoAR regimen (p < 0.05). For early toxicities (α/ß = 10 Gy), a λ-value lower than 0.4 Gy/day favors the HypoAR regimen, which is along with the clinical results. CONCLUSION: Radiobiological analysis favors HypoAR as a safe and effective regimen for high-risk prostate cancer patients, which is confirmed in the current phase II clinical study.

Prognostic and Predictive Relevance of Tumor-Infiltrating Lymphocytes in Squamous Cell Head-Neck Cancer Patients Treated with Radical Radiotherapy/Chemo-Radiotherapy.

Microenvironmental conditions control the entrance and thriving of cytotoxic lymphocytes in tumors, allowing or preventing immune-mediated cancer cell death. We investigated the role of tumor-infiltrating lymphocyte (TIL) density in the outcome of radiotherapy in a series of squamous cell head−neck tumors (HNSCC). Moreover, we assessed the link between markers of hypoxia and TIL density. One-hundred twenty-one patients with HNSCC treated prospectively with radical radiotherapy/chemo-radiotherapy were analyzed. The assessment of TIL density was performed on hematoxylin and eosin biopsy sections before radiotherapy. TIL density ranged from 0.8 to 150 lymphocytes per ×40 optical field (median 27.5). Using the median value, patients were grouped into two categories of low and high TIL density. Early T-stage tumors had a significantly higher TIL density (p < 0.003), but we found no association with N-stage. Overexpression of HIF1α, HIF2α, and CA9 was significantly linked with poor infiltration by TILs (p < 0.03). A significant association of high TIL density with better disease-specific overall survival and improved locoregional relapse-free survival was noted (p = 0.008 and 0.02, respectively), which was also confirmed in multivariate analysis. It is concluded that HNSCC phenotypes that allow for the intratumoral accumulation of lymphocytes have a better outcome following radical radiotherapy/chemo-radiotherapy. Intratumoral-activated HIF- and CA9-related pathways characterize immunologically cold tumors and may be used as targets for therapeutic interventions.

Lipophagy-Related Protein Perilipin-3 and Resistance of Prostate Cancer to Radiation Therapy.

PURPOSE: Radiation therapy is a principal treatment modality for localized and locally advanced prostate cancer (PCa). Metabolic alterations, including lipid metabolism, may reduce treatment efficacy, resulting in tumor relapse and poor therapeutic outcome. In the current study, we investigated the role of the lipophagy-related protein perilipin-3 (PLIN3) and the lysosomal acid lipase (LAL) in PCa response to radiation therapy. METHODS AND MATERIALS: We explored the in vitro and xenograft (in NOD SCID and R2G2 mice) response to radiation of either PLIN3-depleted or LAL-depleted hormone-refractory (DU145, PC3) and hormone-responsive (22Rv1) PCa cell lines. Moreover, we evaluated the clinical role of PLIN3 and LAL protein expression in a series of PCa tissue specimens from patients treated with radical radiation therapy. RESULTS: In vitro and in vivo experiments showed reduced proliferation and strong radiosensitization of all studied PCa cell lines upon PLIN3 depletion. In vivo experiments demonstrated the significantly augmented radiation therapy efficacy upon PLIN3 depletion, resulting in extensive tissue necrosis. Overexpression of PLIN3 in tissue specimens was correlated with an increased MIB1 proliferation index, increased autophagy flux, reduced response to radiation therapy, and poor prognosis. The effect of LAL depletion on radiation therapy was of lesser importance. CONCLUSIONS: Assessment of PLIN3 expression may identify subgroups of patients with PCa who are less responsive to radiation therapy and at high risk of relapse after irradiation. Whether radiation therapy efficacy may be enhanced by concurrent autophagy or PLIN3 inhibition in this subgroup of patients demands clinical evaluation.

Comparative radiobiological analysis and preliminary results of Ultra hypofractionated accelerated radiotherapy for low-risk prostate cancer patients.

PURPOSE: Moderately accelerated hypofractionation (HypoAR) has been recently established as a standard radiotherapy scheme for low-risk prostate cancer. The application of ultra-hypofractionated regimens (ultra-HypoAR), with fraction size above 5 Gy, is also widely tested. METHODS: We applied Image Guided Radiation Therapy (IGRT) ultra-HypoAR delivered with Volumetric Modulated Arc Therapy (VMAT) technique in low-risk prostate cancer patients (5.75 Gy/fraction, 40.25 Gy total dose, two fractions per week). A comparative radiobiological analysis of Dose-Volume Ηistograms (DVH) obtained for target volumes and organs at risk was performed, investigating the advantages and disadvantages of ultra-HypoAR and conventional radiotherapy regimens (CRT). Early clinical results on efficacy and toxicity are also reported. RESULTS: We calculated the Normalized Total Dose (NTD) and NTD with time correction (NTD_T)-based biological Dose- Volume Histograms (bDVH) for bladder and rectum tissue late effects (α/ß=4 Gy) and early effects (α/ß=10 Gy). Ultra-HypoAR produced a significantly lower biological dose burden than CRT, for both early and late responding tissue components of the bladder and rectum, whether calculated for time-correction or not (p<0.0001). Our clinical experience showed that the ultra-HypoAR regimen produced minimal early and late radiation sequelae. The median PSA levels dropped from 9.1 to 0.75 and 0.45 ng/ml at 6 and 12 months, respectively, after the end of therapy. CONCLUSIONS: In conclusion, radiobiological analysis of DVHs and preliminary clinical experience predict a better efficacy and low early and late toxicity profile for the tested seven-fraction VMAT ultra-HypoAR regimen with IGRT.

Long-Term Results of Postoperative Hypofractionated Accelerated Breast and Lymph Node Radiotherapy (HypoAR) with Hypofractionated Boost.

We report long-term results (median follow-up 12 years) of hypofractionated accelerated radiotherapy (HypoAR) in patients treated with breast-conserving surgery. In total, 367 women were treated with HypoAR. Axillary and supraclavicular area (ASA) were treated in patients with involved nodes. In total, 290 patients (scheme A) received 3.5 Gy/day ×10 fractions (breast/ASA) followed by two 4 Gy fractions with electrons to the affected breast quadrant within 16 days. In total, 77 patients (Scheme B) received 2.7 Gy/day for 16 consecutive fractions (breast/ASA) within 22 days, while concurrently, the affected breast quadrant received an electron booster dose of 0.8 Gy for the first 13 fractions. Amifostine was offered to 252/367 patients. Early radiation toxicity was minimal. Regarding late toxicities, symptomatic breast edema was noted in 2.2%, asymptomatic breast fibrosis in 1.9%, and arm lymphedema in 3.7% of patients. Amifostine reduced early radiation dermatitis (p = 0.001). In total, 2.2% of patients developed contralateral breast and 1.6% other carcinomas. Locoregional recurrence (LR) occurred in 3.1% of patients (0% for in situ carcinomas). Positive margins after surgery, extracapsular node invasion, and HER2-enriched/triple-negative tumors were linked with significantly worse LR-free survival. The involvement of more than three nodes and luminal type other than A were independent prognostic variables of metastasis and death events. HypoAR delivering a biological dose of 50-52 Gy to the breast/ASA is a safe and effective therapy for patients treated with conservative surgery. The risk of carcinogenesis is low. Positive surgical margins, extracapsular node invasion, and HER2-enriched/triple-negative phenotypes appear as a cluster of features linked with a higher risk for locoregional relapse.

Is Locally Advanced Head-Neck Cancer One More Candidate for Accelerated Hypofractionation?

BACKGROUND/AIM: Hypofractionated accelerated radiotherapy (HypoAR) is widely applied for the treatment of early laryngeal cancer. Its role in locally advanced head-neck cancer (LA-HNC) is unexplored. PATIENTS AND METHODS: We present results of a prospective trial on 124 patients with LA-HNC, treated with radio-chemotherapy with three different HypoAR fractionations (3.5 Gy/day × 14-15 fractions, 2.7 Gy/day × 20-21 fractions, and 2.5 Gy/day × 21-22 fractions). RESULTS: Protraction of the overall treatment time due to oropharyngeal mucositis was enforced in 18/57 laryngeal, 6/19 nasopharyngeal, and 15/48 cancer patients with other tumors. Regarding late toxicities, laryngeal edema grade 3 was noted in 5/57 patients with laryngeal cancer, while severe dysphagia was noted in 4/124 and tracheoesophageal fistula formation in 1/124 patients. The complete response rates obtained were 73%, 84%, and 67% in patients with laryngeal, nasopharyngeal, and other tumors, respectively. The 3-year locoregional progression-free survival was 58%, 73%, and 55%, respectively. CONCLUSION: HypoAR chemoradiotherapy is feasible, with acceptable early and late radiotherapy toxicities, response rates and LPFS.

Simultaneous determination of chlorothalonil and its metabolite 4-hydroxychlorothalonil in greenhouse air: dissipation process of chlorothalonil.

An analytical method was developed and tested for the simultaneous determination of chlorothalonil and its main metabolite 4-hydroxychlorothalonil, in airborne samples. High performance liquid chromatography equipped with Ultra-violet detector was used to separate and quantify the analytes. Glass microfibre filters for the collection of the analytes' particles were tested. Solid sorbents, such as Tenax, Florisil, XAD-2 and silica gel, were studied to find out the most suitable material for the collection of the analytes in the gas phase. The results have shown that only chlorothalonil was trapped in the vapor phase with highest results obtained when silica gel was the sorbent of choice. Linearity was demonstrated in a wide concentration range 0.01-10.00 mg L(-1). Recoveries from spiked glass microfibre filters and silica gel cartridges for chlorothalonil and 4-hydroxychlorothalonil were almost quantitative. The quantification limits were calculated to be 8.4 and 19.6 ng m(-3) in air for chlorothalonil and 4-hydroxychlorothalonil, respectively. The two analytes spiked on the GF/A filters and silica gel cartridges were proven to be stable for more than 15 days, at 4degrees C and ambient temperature. The applicability of the present method was demonstrated by the analysis of the chlorothalonil and its metabolite in greenhouse air.

Determination of dithiocarbamate fungicide propineb and its main metabolite propylenethiourea in airborne samples.

A simple, rapid and sensitive GC-MS method for the determination of dithiocarbamate fungicide propineb [polymeric zinc propylenebis (dithiocarbamate)] and an improved HPLC procedure for the simultaneous determination of its main metabolite, propylenethiourea, and ethylenethiourea, the main metabolite of all ethylenedithiocarbamates, in airborne samples are described. The method for the analysis of propineb involves the evolution of carbon disulfide (CS(2)), under acidic conditions in the presence of stannous chloride, extraction of the generated CS(2) into a layer of isooctane which is then analyzed for CS(2) content by GC-MS in SIM mode. Under the optimum conditions, the retention time of CS(2) was 1.89 min and the total time of chromatographic analysis was 5 min. Recoveries from spiking glass microfibre filters (GF/A) and silica gel filters were 86+/-7 (n=9) and 89+/-4 (n=9), respectively. The limit of detection is 0.7 ng per filter, which is equivalent to about 0.8-1.0 ng m(-3) in air. In parallel, an HPLC method with ultraviolet detection is presented for the simultaneous analysis of the metabolites. Separation of the two metabolites was attained in less than 5 min. Recoveries from spiking GF/A and silica gel filters for ethylenethiourea were 100+/-1 (n=3) and 98+/-2 (n=3), respectively, while for propylenethiourea were 102+/-1 (n=3) and 98+/-1 (n=3), respectively. The detection limits are about 36-43 and 40-49 ng m(-3) in air for ethylenethiourea and propylenethiourea, respectively. All the analytes spiked in the filters are proven to be stable for more than one month, at -4 degrees C.

Hyphenated chromatographic techniques for the rapid screening and identification of antioxidants in methanolic extracts of pharmaceutically used plants.

Phytochemical analysis is an important scientific research area, which normally relies on a number of rather laborious and time-consuming techniques for compound identification. Isolation of the ingredients of plant extracts in adequate quantities for spectral and biological analysis was the basis of this research. In this paper the possibility of on-line rapid screening of antioxidant components in methanolic plant extracts and their subsequent identification is reported. Based exclusively on hyphenated chromatographic techniques the methanolic extracts of Tilia europea, Urtica dioica, Lonicera periclymenum and Hypericum perforatum are initially screened for their antioxidant components via an on-line DPPH and ABTS radical scavenging technique. Structural elucidation of the active analytes is achieved by means of LC-MS and LC-UV-SPE-NMR. After the determination of the appropriate LC gradient, a minimal number of chromatographic runs with these hyphenated techniques are adequate for the acquisition of the necessary data, leading to the identification of the targeted compounds. Based on their UV, NMR and MS spectra, the antioxidant compounds identified in the extracts under study were found to be either flavonoid glycosides or mono- and dicaffeoylquinic acids. Although the aim of the study was to show the great potential of the LC-UV-NMR-DPPH/ABTS approach for the rapid screening and identification of plant constituents, the results produced in the course of this study also have some merit by themselves. Some of the compounds detected are reported for the first time in the specific plant extracts.

Ion chromatographic method for the simultaneous determination of nitrite and nitrate by post-column indirect fluorescence detection.

This short paper highlights the suitability of ion chromatography with post-column indirect fluorescence detection to determine simultaneously nitrite and nitrate based on the quenching of tryptophan native fluorescence. The method uses an enhanced fluorescence mobile phase containing tryptophan and detects the suppression of fluorescence of the mobile phase due to the elution of the target ions. The phenomenon of fluorescence quenching of tryptophan is highly induced by the presence of phosphate ions. The quenched fluorescence intensity exhibits concentration dependence in the range 1-25 mg/l and 3-65 mg/l for nitrite and nitrate, respectively. The relative standard deviation for five replicates of a standard solution containing a mixture of 5 mg/l of nitrite and 10 mg/l of nitrate lies around 2.8%. This simple coupling technique results in a relatively sensitive, fast, and accurate method, allowing for both qualitative and quantitative analysis of nitrite and nitrate. The method can easily be implemented to real samples such as foodstuffs, fertilizers and soils and is proven to be precise and accurate when compared with reference methods.

Analytical procedure for the in-vial derivatization--extraction of phenolic acids and flavonoids in methanolic and aqueous plant extracts followed by gas chromatography with mass-selective detection.

An in-vial simple method for the combined derivatization and extraction of phenolic acids and flavonoids from plant extracts and their direct determination with GC-MS, is described. The method is taking advantage of the beneficial potentials of phase transfer catalysis (PTC). Catalysts in soluble and polymer-bound form were tested with the latter being the format of choice due to its high reaction yield and facile separation from the rest of the reaction system. Optimization of experimental conditions was established. Chromatographic separation of eight phenolic acids and four flavonoids methylated via the PTC derivatization step was achieved in 45 min. The detection limits for the described GC-MS(SIM) method of analysis ranged between 2 and 40 ng/ml whereas limits of quantitation fall in the range 5-118 ng/ml, with flavonoids accounting for the lowest sensitivity due to their multiple reaction behavior. Four methanolic extracts from Tilia europea, Urtica dioica, Mentha spicata and Hypericum perforatum grown wild in north-western Greece and four aquatic infusions from commercially available Mentha spicata, Origanum dictamnus, Rosemarinus officinalis and Sideritis cretica were analyzed. Good trueness of the method was demonstrated as no matrix effects were found for the analytes concerned.

Phase-transfer catalytic determination of phenols as methylated derivatives by gas chromatography with flame ionization and mass-selective detection.

A convenient method for the GC determination of phenols as methylated derivatives is proposed, taking advantage of the beneficial features of phase-transfer catalysis (PTC). The optimal experimental conditions of pH, temperature, organic solvent, time of extraction-derivatization and amounts of the participating reactants and catalysts, were properly established. Several catalysts in soluble or polymer-bound form were tested. Most of them demonstrated appreciably high-performance characteristics but the polymer-bound catalyst is most favourable due to its facile separation from the rest of the reaction system after the extraction-derivatization. Interferences with the extraction and derivatization yield were not noticed. The chromatographic separation of 11 methylated derivatives of phenols was complete within 23 min. The detection limits of the method, which range from 0.005 to 0.120 microg, are inadequate for drinking water analysis. However, the method was successfully applied to the analysis of fortified composite lake water samples using GC-flame ionization detection and GC-MS in the single ion monitoring mode with the most abundant characteristic ions. Spiked recoveries of phenolics were in the range 94-102%, on the basis of distilled water calibration graph, signifying that PTC determination of phenols is not affected by the composition of such matrices.

Ultrasonic-assisted derivatization reaction of amino acids prior to their determination in urine by using single-drop microextraction in conjunction with gas chromatography.

A derivatization-extraction method that avoids tedious preconcentration steps is established in order to determine amino acids accurately at nanogram levels. The method involves conversion of the analytes of concern to N(O,S)-ethoxycarbonyl amino acid ethyl esters and subsequent extraction by single-drop microextraction (SDME) followed by GC analysis. The reaction proceeds smoothly and rapidly under ultrasonication which removes the bubbles from the bulk solution. Precision is acceptable and 12 non-hydrolyzed amino acids can be determined in urine in this manner. As long as the extraction conditions are consistently applied, quantitative analysis can be performed accurately. The limits of detection were satisfactory in the range 0.010-0.025 microg/ml for GC-FID and 0.26-68 ng/ml for GC-MS(SIM) with 1 ml sample volume.

Determination of plasma, urine, and bovine serum albumin low-molecular-weight carbonyl levels by capillary gas chromatography with electron-capture and mass-selective detection.

Peroxidation of lipids produces low-molecular-weight carbonyl compounds, which are reactive with biological nucleophiles. The analysis of these compounds is often difficult. A multicomponent method for the determination of 11 of them in biological samples is reported. The samples are subjected to a pretreatment-derivatization procedure followed by gas chromatographic analysis with either electron-capture detection (ECD) or mass-selective detection (MSD) in the selected-ion monitoring mode. The procedure involves derivatization of the analyte with 2,4,6-trichlorophenylhydrazine, extraction with n-hexane, and separation of the derivatization products on a nonpolar gas chromatographic column. The concentration of the derivatization reagent, pH, reaction time, temperature, and presence of extraneous ions were investigated to determine the optimal derivatization conditions. Under these conditions, the method allows for the selective detection of low-molecular-weight carbonyl compounds at femtomole levels in several biological materials such as plasma, urine, and bovine serum albumin without interferences. The limits of detection were in the ranges 0.01-0.2 microM for ECD and 0.15-1.5 microM for MSD. The mean procedural recoveries obtained during the method validation were within the range 85-95% and the intra- and interassay standard deviations do not exceed 4.6 and 6.1%, respectively.